Question

Shortly after the introduction of a new​ coin, newspapers published articles claiming the coin is biased. The stories were based on reports that someone had spun the coin 150 times and gotten 81 headsminus​that's 54​% heads. a) font size decreased by 1 Use the Normal model to approximate the Binomial to determine the probability of spinning a fair coin 150 times and getting at least 81 heads. b) font size decreased by 1 Do you think this is evidence that spinning this new coin is​ unfair? Would you be willing to use it at the beginning of a sports​ event? Explain.

Answer 1

a)

we have to find for n=150 trials probability of getting at least 81 heads for fair coin

so

let X is number of heads

so

E(X)=np=150*0.5 =75

Var(X) =npq=150*0.5*0.5=37.5

SD(X) =sqrt(var(X))=sqrt(37.5) =6.12

Now

=1-P(Z<0.98) =1-0.836=0.164

B)

no,this is not enough evidence because we have still chance of 16.4% getting 81 or more heads so may be the instance at which someone got 81 heads out of 150 is out of 16.4% chances

but i will not use this coin for toss becuase people will not happy with this coin